Gout
Crystal-arthritis caused by monosodium urate deposition. Classically a sudden, exquisitely painful big-toe attack — but the long-term picture is a chronic disease driven by elevated uric acid.
What it is
Gout is the clinical disease produced when monosodium urate crystals precipitate out of solution and deposit in joints, soft tissues and the kidneys. The biochemical precondition is hyperuricaemia — uric acid above its solubility limit (~6.8 mg/dL) — but most people with hyperuricaemia never develop gout, and a single gout flare doesn't always show elevated uric acid at the moment of the attack. The classic first presentation is podagra: sudden severe pain, redness and swelling at the base of the big toe, often waking the patient at night, peaking within 24 hours. Without treatment, untreated gout progresses from intermittent flares to chronic tophaceous disease with joint destruction and impaired kidney function.
Key lab markers
- Uric acid — the underlying biochemical lesion; target <6.0 mg/dL on urate-lowering therapy.
- Creatinine + eGFR — kidney function affects uric acid handling and drug choice.
- CRP — elevated during an acute flare.
- WBC — modest elevation during flare can mimic infection.
- Joint fluid analysis — definitive diagnosis comes from seeing crystals under polarised microscopy in joint aspirate, not from blood tests.
Symptoms
- Sudden severe joint pain, often nocturnal
- The big toe is the classic site, but ankle, knee, midfoot, finger, elbow and wrist also common
- Joint redness, warmth, swelling
- Low-grade fever during severe attacks
- Tophi — chalky deposits visible under skin in chronic disease (ear cartilage, elbows, fingers)
- Kidney stones in 10–25% of patients
When to discuss with a doctor
An acute flare needs prompt treatment (NSAIDs, colchicine or corticosteroids) — quicker treatment shortens the attack. Two or more flares per year, tophi, kidney stones, or coexisting CKD are indications for urate-lowering therapy (allopurinol is first-line; febuxostat second). Lifestyle measures matter — reducing red meat, organ meats, seafood and beer; weight loss; avoiding fructose-sweetened drinks — but rarely sufficient alone for severe disease. Mediora.AI flags uric acid trajectory and reminds when the value approaches the action threshold.